4 DefinitionPerformance requirements imply a functional relationship between Power to Weight ratio ( ) and Wing Loading ( ).For each phase of flight, the power to weight ratio is calculated in terms of wing loading.

13 Running the Constraint ProgramDownload and unzip the constraint analysis code(s) from Team Center.In the folder, you will see a program called constraint.m. This is the master program, and it calls all of the other .m files as functions.There is no need to edit the master program, but feel free to take a look at the program and its functions to understand how it works.Run constraint.m in MATLAB, it will prompt you for an input file (contraint_input.dat).Desired constraints can be analyzed by updating the aircraft parameters and flight segments in the input file (contraint_input.dat).The program will output (to the MATLAB command screen) some various values (mostly the data you have input). If you wish to see additional numerical data, feel free to change the program to print out the data.A graph of Wing Loading (oz/ft2) vs. Power to Weight Ratio (Watts/lbf) will be created, showing the energy required for each of the legs of the mission. An example of the output follows.

14 The altitude is MSL (Altitude above Mean Sea Level). The input file is called contraint_input.dat (You can rename it to whatever you want). Here is an example set of inputs:airplaneaspect ratioCdopropellor efficiencymotor efficiencyoswald efficiciencytake offaltitude (ft)Clmaxtakeoff distance (ft)landingaltitude (ft)landing distance (ft)reverse force fractionceilingaltitude (ft)rate-of-climbR/C (ft/sec)max speedairspeed (ft/sec)turnaltitude (ft)airspeed (ft/sec)load factorEdit as requiredEach of the numbers in the input file must have a decimal in it. For example, 1.2, or 75. (not 75).Do not change the order of the different variables. Don’t change anything but the numbers!The altitude is MSL (Altitude above Mean Sea Level).You can repeat certain legs, for example, you can have multiple turn segments, ceilings, etc. To do so, simply add the new flight profiles to the input file. Sequence of flight segments is not important.Mission LegsEdit as required

20 Assumptions The weight fraction is known and achievable0.23 for most competitive AIAA D/B/F aircraft0.40 for AIAA D/B/F competition averageThe motor and propeller efficiencies are constant (not true!)Known 2 term aircraft aerodynamic drag model is applicableEstimate and update based on wind-tunnel testingWind speeds/directions not consideredIncreased power requirement for upwind flight segments with a headwind are not offset by reduced power requirements on the downwind flight segment.Human-in-the-loop – Pilot cannot always operate aircraft at optimal design point!Safety factor required to achieve design performance specification

21 Running the Weight ProgramDownload and unzip the constraint analysis code(s) from Team Center.In the folder, you will see a program called weight.m. This is the master program, and it calls all of the other .m files as functions.There is no need to edit the master program, but feel free to take a look at the program and its functions to understand how it works.Update to input file (weight_input.txt) to include desired aircraft parameters and define different flight segments.Run weight.m in MATLAB, it will prompt you for an input file (weight_input.txt).Aircraft weight break-up and performance summary for each flight leg will be output to the Matlab screen. An example of the output follows.

22 The altitude is MSL (Altitude above Mean Sea Level). The input file is called weight_input.dat (You can rename it to whatever you want). Here is an example set of inputs:airplaneaspect ratioCdospan efficiencypropeller efficiencymotor efficiencywing loading (oz weight/ft2)power to weight (Watt/lbf)energy (Joules) / Battery Weight (lbf)empty weight fraction (emperical)payload weight (lbf)take-offaltitude (ft)Clmaxclimbalitude above ground to climb to (ft)delta (% of max power)c1altitude (ft)cruise distance (ft)c2cruise velocity (ft/s)lot1turn angle (degrees)clmaxt2turn velocity (ft/s)turn angle (degrees)Edit as requiredEach of the numbers in the input file must have a decimal in it. For example, 1.2, or 75. (not 75).Do not change the order of the different variables. Don’t change anything but the numbers!The altitude is MSL (Altitude above Mean Sea Level).You can repeat certain legs, for example, you can have multiple turn segments, ceilings, etc. To do so, simply add the new flight profiles to the input file. Sequence of flight segments is not important.Mission LegsEdit as requiredNote: Climb module available, but current version requires improvement and is not recommended for use.

25 Running the Flight ProgramDownload and unzip the constraint analysis code(s) from Team Center.In the folder, you will see a program called flight.m. This is the master program, and it calls all of the other .m files as functions.There is no need to edit the master program, but feel free to take a look at the program and its functions to understand how it works.Update to input file (flight_input.txt) to include desired aircraft parameters and define different flight segments.Run flight.m in MATLAB, it will prompt you for an input file (flight_input.txt).Aircraft performance summary for each flight leg will be output to the Matlab screen, including energy requirements and surplus. An example of the output follows.

26 The altitude is MSL (Altitude above Mean Sea Level). The input file is called flight_input.dat (You can rename it to whatever you want). Here is an example set of inputs:airplaneaspect ratioCdospan efficiencypropeller efficiencymotor efficiencyEnergy (Joules) / Battery Weight (lbf)payload weight (lbf)empty weight (lbf)battery weightwing planform area (ft^2)motor power (watts)take-offaltitude (ft)Clmaxclimbalitude above ground to climb to (ft)delta (% of max power)c1altitude (ft)cruise distance (ft)c2cruise velocity (ft/s)lot1turn angle (degrees)clmaxt2altitude (ft)turn velocity (ft/s)turn angle (degrees)Edit as requiredEach of the numbers in the input file must have a decimal in it. For example, 1.2, or 75. (not 75).Do not change the order of the different variables. Don’t change anything but the numbers!The altitude is MSL (Altitude above Mean Sea Level).You can repeat certain legs, for example, you can have multiple turn segments, ceilings, etc. To do so, simply add the new flight profiles to the input file. Sequence of flight segments is not important.Mission LegsEdit as requiredNote: Climb module available, but current version requires improvement and is not recommended for use.

31 Main Program (optimize.m)Input aircraft parametersEstablish mission constraint to obtain required specific power requirementsUsually take-off distance requirementSize aircraft for heaviest payload missionEvaluate aircraft performance for other missionsIterate through wing loadings and aspect ratios to optimize parameters of interest!File provided is based on competition and will require to be tailored for each year’s requirements.